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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Mechanical Engineers A
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Journal DOI :
The Korean Society of Mechanical Engineers
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Volume & Issues
Volume 21, Issue 12 - Dec 1997
Volume 21, Issue 11 - Nov 1997
Volume 21, Issue 10 - Oct 1997
Volume 21, Issue 9 - Sep 1997
Volume 21, Issue 8 - Aug 1997
Volume 21, Issue 7 - Jul 1997
Volume 21, Issue 6 - Jun 1997
Volume 21, Issue 4 - Apr 1997
Volume 21, Issue 5 - Jan 1997
Volume 21, Issue 3 - Jan 1997
Volume 21, Issue 2 - Jan 1997
Volume 21, Issue 1 - Jan 1997
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Fuzzy Control Algorithm Eliminating Steady-state Position Errors of Robotic Manipulators
Kang, Chul-Goo ; Kwak, Hee-Sung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 361~368
DOI : 10.22634/KSME-A.19188.8.131.521
In order to eliminate position errors existing at the steady state in the motion control of robotic manipulators, a new fuzzy control algorithm is propeosed using three variables, position error, velocity error and integral of position errors as input variables of the fuzzy controller. Although the number of input variables of the fuzzy controller is increased from two to three, the number of fuzzy control rules is just increased by two. Three dimensional look-up table is used to reduce the computational time in real-time control, and a technique reducing the amount of necessary memory is introduced. Simulation and experimental studies show that the position errors at the steady state are decreased more than 90% compared to those of existing fuzzy controller when the proposed fuzzy controller is applied to the 2 axis direct drive SCARA robot manipulator.
A Study on the Basic Design of a Torque Converter Using Equivalent Performance Model
Jang, Wook-Jin ; Lim, Weon-Sig ; Lee, Jang-Mooee ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 369~377
DOI : 10.22634/KSME-A.19184.108.40.2069
The torque converter, a major part of automatic transmissions, has many difficulties in analysis due to the factors such as power transmission through fluid flow, complex internal geometry, and various operating conditions. Because of such difficulties, the dynamic analysis and design of a torque converter are generally carried out by using equivalent performance model which is based on the concept of mean flow path. Since the design procedures of a torque converter are essential technology of automotive industry, the details of the procedures are rarely published. In this study, the basic design procedures of a torque converter are systemized and coded based on the equivalent performance model. The mathematical methods to deal with mean flow path determination and the core-shape are developed. And by using this model, the method of determination of performance parameters satisfying the requested performance is proposed. Finally, to embody the three-dimensional shape, the intermediate blade angles which maximize the tractive performance are determined and laid out.
A Study on the Curing Bladder Shaping of Tire by Finite Element Method Using Contact Element
Kim, Hang-Woo ; Hwang, Gab-Woon ; Cho, Kyu-Zong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 378~384
DOI : 10.22634/KSME-A.19220.127.116.118
In curing process of tire, contact and slip occurs between green tire and curing bladder. The curing process is a critical step in the manufacture of tires. In this investigation, curing bladder shaping is examined using a finite element method. Specifically, a finite element model between the inner part of green tire and the outer part of curing bladder is generated using contact element and curing bladder is generated using incompressible element. Numerical analysis are performed on two different bladder types, different overall outer diameters of curing bladder and different heights of curing bladder. Numerical results show that contact pressure is increased by using toroidal type of curing bladder, increasing overall diameter and increasing height of curing bladder. To obtain natural equilibrium carcass line, there is a requirement in increasing contact pressure of the section between side and bead.
A Study on the Strength and Failure Mode of Co-cured Composite Joints
Choi, Jin-Ho ; Lee, Dae-Gil ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 385~392
DOI : 10.22634/KSME-A.1918.104.22.1685
The joint design and manufacture of the composite structure have become an important research area because the structural efficiency of the composite structure is often determined by its joint not by its basic structure. The co-cured joint is an efficient joint technique because both curing and jointing for composite structures are achieved simultaneously. In this paper, the torque capacities of the co-cured tubular lap joint with and without knurling of the pyamid type were experimentally measure. From the experimental resuts, it was found that the excess resin played a role as an adhesive in the co-cured tubular lap joint whose steel adherends were not knurled. Also, it was found that the torque capacity of the co-cured joint was increased as the knurling size of the pyramid type on the surface of the steel adherend was increased.
Measurement of Stress Intensity Factor of Isotropic Material Using SPATE
Hwang, Jae-Seok ; Seo, Jae-Guk ; Lee, Hyo-Jae ; Nam, Jeong-Hwan ; Rowlangs, R.E. ; Choe, Yeong-Cheol ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 393~404
DOI : 10.22634/KSME-A.1922.214.171.1243
SPATE(Stress Pattern Analysis by Thermal Emission) can be effectively used to analyze the stress distributions of isotropic structure under the repeated load by non-contact. In this research, the measuring method and the measuring concept of stress intensity factor of isotropic material by SPATE are suggested. The validity of the method and the concept was certified through SPATE experiment.
Material Properties and Strengthening Mechanism in Shape Memory TiNi Fiber Reinforced Al Matrix composite
Park, Yeong-Cheol ; Yun, Du-Pyo ; Lee, Gyu-Chang ; Huruya, Y. ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 405~413
DOI : 10.22634/KSME-A.19126.96.36.1995
In the present paper, it is attempted to reconfirm the "Intelligent" material properties using both the sintered TiNi/Al(1100) matrix composite made by powder metallurgy method and the squeeze-casted TiNi/Al6061 specimens. A metal matrix composite is, its fault has been considered to deteriorate a strength of composite by heating residual stress of the matrix. Therefore, it is necessary to remove a tensile residual stress, to produce the strength of a composite better. On the contrary, if compressive residual stress happens in matrix of composite in place of tensile residual stress, it will make the strength of composite better. So that, this paper introduce the development of a high strength of composite, by using compressive residual stress well, on the study. By using these specimens, shape memory strengthening effects in tensile strength and fatigue crack propagation above inverse transformation temperature of TiNi fiber were investigated. We occurs the prestrain and volume fraction for to discuss the effects of a composite strength. Moreover, by SEM observation, the effect of the residual stress at the interface between Al matrix and TiNi fiber and some brittle precipitation layers such as inter metallic compounds on fracture mechanisms was discussed metallurgically.urgically.
The Evaluation of the Kinked Interface Crack Behavior in Dissimilar Materials by CED
Kwon, O.H ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 414~422
DOI : 10.22634/KSME-A.19188.8.131.524
The characteristics on the extension of the CED(Crack Energy Density) concept to the interface kinked crack problems in a dissimilar are examined. Each mode contributions of CED are found by symmetric and antisymmetric conponents and domain independent integrals. Finite element calculation is carried out to simulate the interface kinked crack growth on a bimaterial. The focus is the establishment of fracture criterion with CED and finding the orientation of crack extension. From the results, a prediction about the extension behavior of an interface kinked crack can be done. And we show that CED can be a parameter to indicate fracture criterion at an interface kinked crack.
A Simplified Method for Determining Modal Strain Energy Release Rate of Free-Edge Delaminations in Laminated Composite
Kim, Taek-Hyun ; Oh, Taek-Yul ; Kim, In-Kweon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 423~429
DOI : 10.22634/KSME-A.19184.108.40.2063
A simplified method for determining the mode components of the strain energy release rate of free-edge delaminations in laminated composite is proposed. The interlaminar stresses are evaluated as an interface moment and interface shear forces that are obtained from the equilibrium equations at the interface between the adjacent layers. Deformation of an edge-delaminated laminate is calculated by using a generalized quasi-three dimensional classical laminated plate theory developed by the authors. The analysis provides closed-form expression for the three components of the strain energy release rate. Comparison of results with a finite element solution using the virtual crack closure technique shows good agreement. In the present study, laminated composite with stacking sequences of [30/-30/90]
were examined. The simple nature of the method makes it suitable for primary design analysis for the delaminations of laminated composite.e.
Electrochemical Deburring System by the Electroplated CBN Wheel
Choe, In-Hyu ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 430~438
DOI : 10.22634/KSME-A.19220.127.116.110
Deburring and edge finishing technology as the final process of machining operation is required for manufacturing of advanced precise conponents. But, deburring is considered as a difficult problem on going to the high efficient production and automation in the FMS. Removal of burr couldn't have a standard of its definition because of its various shapes, dimensions and properties and mostly depends on manual treatment. Especially, deburring for cross hole inside is very difficult owing to its shape passing through out perpendicular to a main hole. The electrochemical method is suggested as its solution in practical aspect. Therefore, electrochemical deburring technology needs to be developed for the high efficiency and automation of internal deburring in the cross hole. In this study, the new process in the eliminating burr inside cross hole, electrochemical deburring by the wheel electroplated with Cubic-Boron-Nitrade abrasives, is suggested. Its deburring mechanism is described and machining performances is investigated. Also, CBN electroplated wheel is designed and manufactured and then characteristics of electrochemical deburring are investigated through experiments. Overall electrochemical deburring performance against burr inside cross hole is examined in the various power sources such as peak current and direct current.
Thermal Stress Analysis of Functuonally Graded Ceramic/Metal Composites(I)-Plasma Spraying Material-
Song, Jun-Hee ; Lim, Jae-Kyoo ; Chung, Se-Hi ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 439~446
DOI : 10.22634/KSME-A.1918.104.22.1689
A traditional notion of composites has been composed as a uniform dispersoid, but now it is proposed without regard to such rule with process development. Functionally Graded Material(FGM) consists of a new material design that is to make intentionally irregular dispersion state. In this study, thermal stress analysis of plasma spraying PSZ/NiCrAlY gradient material was conducted theoretically using a finite-element program. A formations of the model are direct bonding material(NFGM) and FGM with PSZ and NiCrAlY component element. The temperature conditions were
to 1100.deg. C assuming a cooling-down precess up to room temperature. Fracture damage mechanism was analyzed by the parameters of residual stress.
Stress intensity factor of semi-infinite parallel crack propagated with constant velocity in dissimilar orthotropic strip under out-of-plane deformation
Park, Jae-Wan ; Kwon, Yong-Su ; Jeong, Jae-Tack ; Choi, Sung-Ryul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 447~456
DOI : 10.22634/KSME-A.1922.214.171.1247
Stress intensity factor of semi-infinite parallel crack propagation with constant velocity in dissimilar orthotropic strip under out-of-plane clamped desplacement is investigated. Using Fourier integral transforms the boundary value problem is derived by a pair of dual integral equation and finally reduced to a single Wiener-Hopf equation. By applying Wiener-Hopf technique the equation is solved. Applying this result the asymptotic stress fields near the crack tip are determined, from which the stress intensity factor is obtained in closed form. The more the ratio of anisotropy or the ratio of bi-material shear modulus increase in the main material including the crack, the more the stress intensity factor increases. Discontinuity in the stress intensity factor is found as the parallel crack approaches the interface. In special case, the results of isotropic materials agree well with those by the previous researchers.
A Study on the Side Drop Impact of a Nuclear Spent Fuel Shipping Cask
Chung, Sung-Hwan ; Lee, Young-Shin ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 457~469
DOI : 10.22634/KSME-A.19126.96.36.1997
A nuclear spent fuel shipping cask is required by IAEA and domestic regulations to withstand a 9m free drop condition. In this paper, the structural analysis under the 9m side drop condition was performed to understand the dynamic impact behavior and to evaluate the safety of the cask for 7 PWR nuclear spent fuel assemblies. The analysis result was compared with the measured value of the 9m side drop test for the 1/3 scaled-down model and the accuracy of the 3D analysis was confirmed. Analysis in accordance with the diameter of impact limiters for the proto-type cask were performed. Through the analysis, the impact behaviors due to the side drop and the effects dependent on the diameter of impact limiters were grasped. Maximum stress intensities on each part of the cask were respectively calculated by using the stress evaluation program and the structural safety of the cask was finally evaluated in accordance with the regulations.
Development of a Fault-tolerant Intelligent Monitoring and Control System in Machining
Choi, Gi-Heung ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 470~476
DOI : 10.22634/KSME-A.19188.8.131.520
The dynamic characteristics of industrial processes frequently cause an abnormal situation which is undesirable in terms of the productivity and the safety of workers. The goal of fault-tolerance is to continue performing certain activities even after the failure of some system cononents. A fault-tolerant intelligent monitoring and control system which is robust under disturbances is proposed in this paper. Specifically, the fault-tolerant monitoring scheme proposed consists of two process models and the inference module to preserve such a robustness. The results of turning experiments demonstrate the effectiveness of the fault-tolerant scheme in the presence of built-up edge.
Large Force Measuring System Using Build-up Technique;
Kang, Dae-Im ; Song, Hou-Keun ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 477~484
DOI : 10.22634/KSME-A.19184.108.40.2067
This paper describes the build-up force measuring system of 9.9 MN capacity which consists of nine force transducers of each having 1.1 MN capacity. We have specially designed a force transducer for a build-up force measuring system to reduce the uncertainty of a build-up system and to accomodate the new test procedure for a build-up system. It reveals that the relative uncertainty of the force measuring system is less than 1.5*10
in the ran9e of 1-4.5 MN irrespective of loading direction. The force measuring system may be used to calibrate a 10 MN force standard machine to be used as a large force standard in Korea.
A Study on the Pressure Control Characteristics of ON/OFF 3-way Solenoid Valve Driven by PWM Signal
Jeong, Heon-Sul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 485~501
DOI : 10.22634/KSME-A.19220.127.116.115
Pressure control is possible driving a simple ON/OFF 3-way valve of hydraulic servo system by pulse width modulation signal. But the pressure varies according to the duty ratio and carrier frequency and repeated on-off action induces pressure fluctuation. So equations for mean pressure and ripple amplitude are theoretically derived as a function of on/off time, the system parameters which decide the pressure characteristics are arranged and they are verified by experimental study. As the result selection criteria for the major design parameters are established and the basic strategy to suppress the unnecessary fluctuation can be provided for a hydraulic pressure control system using these type of valves.
Multivariable Control of Cold-Rolling Mills with Roll Eccentricity
Kim, Jong-Sik ; Kim, Seung-Su ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 502~510
DOI : 10.22634/KSME-A.1918.104.22.1682
A disturbance rejection controller using eccentricity filtering and LQ control techniques is proposed to alleviate the effecto of major roll eccentricity in multivariable cold-rolling processes. Fundamental problems in multivariable cold-rolling processes such as process time delay inherent in exit thickness measurement and non-stationary characteristics of roll eccentricity signals can be overcome by the proposed control method. The filtered instantaneous estimate of roll eccentricity may be exploited to improve instantaneous estimate of the exit thickness variation based on roll force and roll gap measurements, and a feedforward compensator is augmented as a reference for a gaugemeter thickness estimator. LQ feedback controller is combined with eccentricity filter for the attenuation of the exit thickness variation due to the entry thickness variation. The simulation results show that the roll eccentricity disturbance is significantly eliminated and other disturbances also are attenuated.
An experimental study on the fretting fatigue crack behaviour of A12024-T4
Lee, Bong-Hun ; Lee, Sun-Bok ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 511~518
DOI : 10.22634/KSME-A.1922.214.171.1241
The technique of fretting fatigue test was developed and fretting fatigue tests of A12024-T4 were conducted under several conditions. The newly developed calibration methods for measuring surface contact tractions showed good linearity and repeatability. The plate type specimen to which tow bridge type pads were attached and vision system was used to observe the crack behaviour. The oblieque cracks appeared in the early stage of crack growth and they became mode I cracks as they grow about 1 mm. The mode I transition points were found to be longer when surface tractions are higher or bulk stress is lower. Before the crack becomes mode I crack, 'well point' where crack grow about rate is minimum, was detected under every experimental condition. The crack behaviour was found to be affected by surface tractions, contact area, bulk stress. It was also found that partial slip and stick condition is most detrimental and the crack starts from the boundary of stick and slip. For gross slip crack started at the outside edge of pad. After crack mode transition, fretting fatigue cracks showed almost same behaviour of plain mode I fatigue cracks. Equivalent stress intensity factor was used to analyze the behaviour of fretting fatigue cracks and it was found that stress intensity factors can be applied to fretting fatigue cracks.
Evaluation of Elastic-Plastic Fracture Toughness of Aged AISI 316 Steel Using DC-electric Potential Method
Lim, Jae-Kyoo ; Chang, Jin-Sang ; Lino, Y. ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 519~527
DOI : 10.22634/KSME-A.19126.96.36.1999
AISI 316 steel has been used extensively for heater and boiler tube of the structural plants such as power, chemical and petroleum plants under severe operating conditions. Usually, material degradation due to microcrack or precipitation of carbides and segregation of impurity elements, is occured by damage accumulated for long-term service at high temperature in this material. In this study, the effect of aging time on fracture toughness was investigated to evaluate the measurement of material degradation. The elastic-plastic fracture toughness behaviour of AISI 316 steel pipe aged at
for 1h-10000h (the aged material) was characterized using the single specimen J-R curve technique and eletric potential drop method at normal loading rate(load-line displacement speed of 0.2mm/min) in room temperature and air environment. The fracture toughness data from above experiments is compared with the
obtained from predicted values of crack initiation point using potential drop method.
The Measurement of the Crack in CCT Specimen Using the Image Processing Techniques
Lee, Hyun-Woo ; Mun, Gi-Tae ; Oh, Se-Jong ; Jeong, Byung-Woo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 21, issue 3, 1997, Pages 528~533
DOI : 10.22634/KSME-A.19188.8.131.528
In the analysis of fatigue crack propagation behavior, the crack length is one of the most important factors. In the test of crack propagation, compliance method is widely used to detect crack length. The measurement of surface crack length is not so easy with compliance method. In this study, the image processing technique was applied to measure the surface crack length. CCD(Charge-coupled device) camera was used to observe the crack image and the computer program to detect crack length from stored crack image was developed. CCT(Center Cracked Tension) specimen was used to compare the compliance method with the image processing technique. The crack length which detected by the image processing techniques was found to be well consistent with that from the optical measurement.